In 18th-century Korea, Prince Yi San is a perfectionist haunted by his father's murder. He's set to inherit the throne once his cruel grandfather, the current king, passes away. Despite the emotional scars left by his father's death, Yi San aspires to be a benevolent ruler who reforms the kingdom's laws. At court, he encounters Sung Deok Im, a spirited and intelligent young woman. While Yi San falls in love and proposes she become his concubine, Sung Deok Im grapples with the restrictions and responsibilities that come with royal life. However, as their love deepens, she begins to see the potential to bring positive change to the troubled realm through their union.
Fang Jia Hua is the successor of a business. His dream is to open a chocolate store and be an expert in chocolate. He ends up leaving his business and his family to fulfill his dream. Hong Xi En is someone who spent her days slogging and taking up part time work. One day, she ends up working for him and above all, she has to dress herself as a man for the job.